Claims:We claim:
1. An online system for monitoring healthiness of spring loaded hangers (1) in high pressure steam generators, the online system comprising:
a spring loaded hangers (1) having a compressible spring (4) supported by a supporting structure (2) which carries a hot working load (3);
a force transducer means (5) mounted on the compressible spring (4) to provide output signal in relation to corresponding changers in compressible spring dimensions;
a signal conditioning means (6) coupled with the force transducer means (5) via hardware interface to receive the output signal and converts the signals into conditioned signal with a processor;
a signal processing means (7) coupled with the signal conditioning means via the processor to process the conditioned signal by comparing the conditioned signal with set points to identify actual level of stress acting on the compressible spring (4); and
a signal monitoring/annunciating and human machine Interface means (8) coupled with the signal processing means (7) via the processor to indicate/annunciate for maintenance/ action to be taken on the load hangers.
2. The online system as claimed in claim 1, wherein the force transducer (5) converts force exerted to a relative electric signal.
3. The online system as claimed in claim 1, wherein the force transducer (5) is typically mechanical type like Strain gauge type load cell or optical type like Fiber based strain sensor.
4. The online system as claimed in claim 1, wherein the signal conditioning means (6), the signal processing means (7), the Signal monitoring/annunciating and human machine Interface means (8) are connected over network with the spring loaded hangers (1).

5. An online system for monitoring healthiness of spring loaded hangers (1) in high pressure steam generators, the online system comprising:
a plurality of spring loaded hangers (1) where each having a compressible spring (4) supported by a supporting structure (2) which carries a hot working load (3);
a force transducer means (5) mounted on the compressible spring (4) of each of the plurality of spring loaded hangers (1) to provide output signal in relation to corresponding changes in the compressible spring (4) dimensions;
a selector (9) is coupled with the plurality of force transducer means (5) via hardware interface to sample the data and select a particular force transducer for monitoring, wherein the plurality of force transducer signals available from the plurality of spring loaded hangers (10) which either carries a common working load or a different working load are processed in the common signal processor with the sample selector (9) such that healthiness of the spring loaded hanger support systems are continuously monitored online;
a signal conditioning means (6) coupled with the force transducer means (5) via hardware interface to receive the output signal and converts the signals into conditioned signal with a processor;
a signal processing means (7) coupled with the signal conditioning means via the processor to process the conditioned signal by comparing the conditioned signal with set points to identify actual level of stress acting on the compressible spring (4); and
a signal monitoring/annunciating and human machine Interface means (8) coupled with the signal processing means (7) via the processor to indicate/annunciate for maintenance/ action to be taken on the load hangers.

6. The online system as claimed in claim 5, wherein the force transducer (5) converts force exerted to a relative electric signal.
7. The online system as claimed in claim 5, wherein the force transducer (5) is typically mechanical type like Strain gauge type load cell or optical type like Fiber based strain sensor.
, Description:ONLINE SYSTEM FOR MONITORING THE HEALTHINESS OF SPRING LOAD HANGERS IN HIGH PRESSURE STEAM GENERATORS
FILED OF INVENTION:
[001] The present subject matter described herein relates to load carrying supports of variable or constant load in Vertical Hanging type High pressure steam generators and, in particularly, to a method and apparatus for signaling the movement of Vertical load hangers thereby ensuring the healthiness of the spring support hangers by online monitoring system.
BACKGROUND OF INVENTION:
[002] Variable load hangers & Supports are used where the load variation between the pre-set and operating condition is less than 25%, when the load variation exceeds 25% of the initial pre-set load, then constant load hangers/supports are preferable. For critical piping system, where no residual stresses are to be transferred to the pipe, constant load hangers/supports are used.
[003] Presently the healthiness of the load hanger system is monitored manually by visual inspection carried out locally by the operation & maintenance personal periodically.
[004] Colin J. Salter (U.S. Pat. No. 4,206,898) discloses the arrangement of constant spring supports with the standard form of lever for a particular range of loads in which the carrier position shall be varied for different loads by which the load connecting means to the lever shall be varied.
[005] Norman Whitney & Frank J. Birch (U.S. Pat. No. 5,944,288) discloses the arrangement by which a constant support pipe hanger suitable for use in both horizontal and vertical orientations.
[006] However none of these prior art inventions deal with healthiness monitoring of spring supports hangers.
[007] However there exists a need for online monitoring of healthiness of load hanger operation to ensure load transfer to be safe and effective. The present invention describes a system to monitor the healthiness of load hanger operation.
SUMMARY OF INVENTION:
[008] In a field implementation, several transducer signals available from multitude of hangers are processed in the common signal processor such that healthiness of the plant’s spring loaded hanger support systems are continuously monitored online.
[009] The force transducer means deployed converts force exerted to relative electric signal and can be typically mechanical type like Strain gauge type load cell or optical type like Fiber based strain sensor.
[0010] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWING:
[0011] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0012] FIGURE-1: illustrates the arrangement of spring support hanger with hot load and the support spring with force transducer on it, in accordance with an embodiment of the present subject matter;
[0013] FIGURE-2: illustrates the schematic arrangement of spring support hanger healthiness monitoring system, in accordance with an embodiment of the present subject matter;
[0014] FIGURE-3 illustrates the schematic of multiple spring support hanger monitoring system with single processing unit, in accordance with an embodiment of the present subject matter;
[0015] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT:
[0016] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0017] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.

[0018] FIGURE-1: illustrates the arrangement of spring support hanger with hot load and the support spring with force transducer on it, in accordance with an embodiment of the present subject matter. The Hot working load 3 is supported by the supporting structure 2 which carries this working load with variable/constant spring support hangers 1. The spring support hangers or load carrying member 1 can be made of any existing support hanger.
[0019] The load carrying member 1 has a compressible spring 4. The stress exerted on the compressible spring 4 due to the hot working load 3 is monitored by a system through which the healthiness of the load carrying hanger 1 is ensured. This is done by incorporating a force transducer means 5 including but not limited to mechanical strain gauge, fiber optical strain gauge mounted on the compressible spring 4. The force transducer 5 output signal changes in relation to the corresponding changes in the hanger spring 4 dimensions. The transducer output signal is processed via an online signal processor that generates hanger healthiness status.
[0020] Figure 2 illustrates the system 10 consists of load carrying support hanger 1 supported by the supporting structure 2 which carries the hot load 3. Further, the force transducer means 5 mounted on the supporting compressible spring 4 of the supporting hanger 1 which senses the stress acting on the spring 4 support.
[0021] The Signal output from the force measuring transducer 5 output is amplified and converted to a suitable signal in signal conditioning means a standard electronic signal preparation means consisting of input noise suppressor, instrumentation signal amplifier and signal convertor 6, the field signal is processed in the signal processing means a standard electronic signal processing means consisting of a comparator that qualifies the input based on the pre-defined reference set value of the parameter of interest 7 by comparing with the set points to identify the actual level of stress acting on the spring support.
[0022] When the average deviation output comparatively lesser than our preset deviation limit indicates that the absence of change in stress on the load carrying spring hanger.
[0023] The excess of deviation indicates the increase in stress acting on the spring support, this output is processed with signal monitoring/annunciation/interface means 8 to indicate/ annunciate for maintenance / precautionary action on the load hangers.
[0024] The present online monitoring system monitors healthiness of spring loaded hangers in high pressure steam generators. The online monitoring system has a processor, a hardware interface, a memory, a signal conditioner 6, signal processor 7, monitoring interface 8, a force transducer 5, and a spring loaded hangers 1. In the online monitoring system processor is coupled with the signal conditioner 6, the signal processor 7, and the monitoring interface 8 to receive and process the data in form of signals. The processor(s) may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor(s) is configured to execute computer-readable instructions stored in the memory for performing and processing the signals.
[0025] The processor(s) may be provided through the use of dedicated hardware as well as hardware capable of executing computer readable instructions or logics in association with appropriate software. Moreover, explicit use of the term “processor” should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read only memory (ROM) for storing software, random access memory (RAM), non-volatile storage. Other hardware, conventional and/or custom, may also be included.
[0026] The hardware interface may include a variety of software and hardware interfaces, for example, interfaces for peripheral device(s), such as transducers and an external memory. The hardware interface is suitable for interfacing with the force transducer 5 as referred in the figure 2 and 3. The memory can include any computer-readable medium known in the art including, for example, volatile memory, such as static random access memory (SRAM) and dynamic random access memory (DRAM), and/or non-volatile memory, such as read only memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and magnetic tapes. The processor is operatively coupled with the memory and the hardware interface to execute the instructions for running the monitoring the spring loaded hanger. These instruction or logics may be encoded in the programs that are stored in the memory. Further, all the output of the system and calculation of the spring loaded hanger also stores in the memory for future determinations.
[0027] As shown in the figure 2, the signal conditioning means 6 is connected to the force transducers via hardware interface to receive signals for real time monitoring. The force transducer 5 which is mounted on the compressible spring 4 converts the force exerted to a relative electric signal and can be typically mechanical type like Strain gauge type load cell or optical type like Fiber based strain sensor. The signal conditioning means 6 receives signals from the force measuring transducer 5 which senses the stress acting on the spring support. The signal conditioning means 6 converts the signal into suitable signal for further processing by conditioning. The signal processing means 7 coupled with the processor to process the field signal by comparing the conditioned signal with the threshold set points to identify the actual level of stress acting on the spring support. If the average deviation output comparatively lesser than our preset deviation limit indicates that the absence of change in stress on the load carrying spring hanger. In another case, if excess of deviation indicates the increase in stress acting on the spring support, this output is processed with signal monitoring/annunciation/interface means 8 to indicate/ annunciate for maintenance / precautionary action on the load hangers. The monitoring interface 8 coupled with the signal processing means 7 via the processor indicate the action to be taken.
[0028] Figure 3 illustrates a sensing method by grouping a group of load hangers which will either carry a common load or a different load and the force transducer 5 output from each load hangers are processed by a common electronic means in which the data from each load hangers are sampled with a selector 9. The common signal conditioning 6 and processing 7 means generates the output in comparison with its predefined set point limits. The processed output of each force transducer will be monitored/interfaced with Human Machine Interface (HMI) for maintenance/ precautionary action.
[0029] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.